I. Knowledge related to QMS (Quality Management System)
Eight management principles of QMS
The eight management principles of QMS are the cornerstone for building a quality management system.
1. Customer focus: In the business world, customers are the lifeline of an enterprise. All activities of an enterprise should revolve around meeting customer needs, expectations, and preferences. Only by deeply understanding customers can an enterprise produce products or services that meet market demands and thus gain a foothold in the fierce market competition. For example, Apple has continuously launched innovative products by accurately grasping consumer needs and won the favor of consumers worldwide.
2. Leadership role: Leaders are the helmsmen of an enterprise. Their decisions and actions play a decisive role in the development direction of the enterprise. Excellent leaders can set clear goals and directions for the enterprise, create a positive corporate culture, and motivate employees to strive for the achievement of the enterprise's goals. For example, Ren Zhengfei of Huawei has led Huawei to achieve world - renowned achievements in the communication field with his outstanding leadership ability.
3. Full participation: Quality management is not just the responsibility of the management. Every employee is a participant in quality management. The active participation of employees can improve work efficiency and quality because they are the ones directly involved in the production process and know the problems and areas for improvement best. Only when all employees work together can the effective operation of the quality management system be ensured.
4. Process approach: Regarding quality management as a series of interrelated processes helps enterprises better understand and control the entire production process. By identifying, analyzing, and optimizing these processes, enterprises can improve product quality and production efficiency. For example, automobile manufacturing enterprises ensure that each link meets the quality standards through refined management of the production process.
5. Systematic approach to management: Regard the quality management system as an integrated whole system, where all parts are interrelated and mutually influential. Enterprises need to comprehensively consider various factors, conduct overall planning and coordinated management to achieve the optimal performance of the system.
6. Continuous improvement: The market is constantly changing, and customers' needs are also continuously upgrading. Only by continuously improving the quality management system can an enterprise adapt to market changes and maintain its competitiveness. Continuous improvement is an endless process, which requires enterprises to constantly look for opportunities for improvement and take effective measures for implementation.
7. Decision-making approach based on facts: Decision-making is the core link in enterprise management, and decision-making based on facts can improve the scientific nature and accuracy of decisions. Enterprises need to collect and analyze relevant data and information, make decisions based on objective facts, and avoid subjective assumptions and blind decision-making.
8. Mutually beneficial relationship with suppliers: An enterprise and its suppliers are a community of interests. A good cooperative relationship helps both parties achieve win - win results. The enterprise should establish a long - term and stable cooperative relationship with suppliers, jointly improve product quality and service levels, reduce costs, and enhance market competitiveness.
Contents included in ISO (QMS)
ISO (QMS) includes multiple important standards, providing comprehensive guidance for enterprises' quality management.
1. ISO9001:2000 Requirements for Quality Management Systems: This standard specifies the basic requirements for a quality management system. By establishing and implementing a quality management system that complies with this standard, enterprises can ensure that the quality of their products and services meets the requirements of customers and relevant laws and regulations.
2. ISO 9000:2000 Quality management system - Terms and definitions: Unified terms and definitions are the foundation for ensuring effective communication and understanding of the quality management system. This standard provides clear definitions for various concepts and terms in the field of quality management, which facilitates communication and cooperation both within and outside the enterprise.
3. ISO 9004:2000 Quality management systems - Guidelines for performance improvements: It provides guidance for enterprises on how to further enhance the performance of the quality management system. Enterprises can, based on their own actual situations, refer to the suggestions of this standard and take corresponding measures to achieve continuous improvement of the quality management system.
4. ISO 19011:2000 Guidelines for quality and environmental management systems auditing: This standard provides guidance for enterprises to conduct audits of quality management systems and environmental management systems. Auditing is an important means to ensure the effective operation of the quality management system. Through auditing, problems can be identified, corrective measures can be taken in a timely manner, and the quality management level can be improved.
ISO spirit
The ISO spirit emphasizes "consistency between what is said, what is written, and what is done." This means that in the process of quality management, the policies, procedures, and standards formulated by an enterprise should be in line with actual actions. Only by being consistent in words and deeds can the effective implementation of the quality management system be ensured and the quality of products and services be improved.
Six essential non - deletable contents in the 2000 version of ISO9001
1.4.2.3 Document control: Documents are an important part of the quality management system. Effective control of documents can ensure their accuracy, completeness, and traceability. Enterprises need to establish document management procedures to strictly manage the processes of document preparation, review, approval, distribution, use, modification, and cancellation.
2.4.2.4 Record control: Records are evidence of quality management activities and can reflect an enterprise's quality management level and product quality status. Enterprises need to properly preserve and manage records to ensure their authenticity, integrity, and traceability.
3.8.2.2 Internal quality system audit: Internal audit is an important means for enterprises to conduct self - inspection and improve the quality management system. By carrying out internal audits regularly, enterprises can identify problems in the quality management system, take corrective measures in a timely manner, and ensure the effective operation of the quality management system.
4.8.3 Control of non-conforming products: The existence of non-conforming products can affect the product quality and the reputation of the enterprise. The enterprise needs to establish a control procedure for non-conforming products to promptly identify, isolate, review and handle non-conforming products, and prevent non-conforming products from entering the market.
5.8.5.2 Corrective actions: When problems are found in the quality management system, the enterprise needs to take corrective actions to eliminate the causes of the problems and prevent them from recurring. The implementation of corrective actions requires clear responsible persons and time requirements to ensure the effective execution of the measures.
6.8.5.3 Preventive measures: Preventive measures are important means for enterprises to proactively identify potential problems and take actions to avoid their occurrence. Through data analysis and risk assessment of the quality management system, enterprises can detect potential problems in advance, take corresponding preventive measures, and reduce quality risks.
Classification of quality system audits
1. An enterprise's self - audit of its quality system helps the enterprise to promptly identify its own problems, and achieve self - improvement. Through internal audits, enterprises can continuously optimize their quality management systems, improve product quality and management levels.
2. The customer or their representative conducts an audit of the supplier's quality system to ensure that the supplier can provide products and services that meet the requirements. Such an audit can prompt the supplier to strengthen quality management, improve product quality, and meet the customer's needs.
3. Certification: The quality system audit of an enterprise conducted by a certified registered company or other impartial third parties is independent and fair. Its purpose may be for certification and registration, or for evaluating the enterprise's quality management level. Through the third - party audit, the enterprise can obtain authoritative certification and enhance its market competitiveness.
Internal quality system audit basis
1. Relevant national laws and regulations: Enterprises must abide by national laws and regulations to ensure that their products and services meet national quality standards and safety requirements. Laws and regulations are the bottom line for enterprise quality management. Violating laws and regulations will lead to serious legal consequences.
2. Industry-specific quality management and various quality assurance standards: Different industries have different quality standards and requirements. Enterprises need to follow the specific standards of the industry to ensure that their products and services comply with industry regulations. For example, the food industry needs to comply with food safety standards, and the medical industry needs to comply with medical device quality standards.
3. International Quality Management and Assurance Standards: With the development of economic globalization, enterprises need to participate in international market competition and follow international quality management and assurance standards. These standards can enhance the international competitiveness of enterprises and promote their international development.
4. Quality Manual: The quality manual is a guiding document for an enterprise's quality management system, which stipulates the enterprise's quality policy, objectives, and the basic requirements of the quality management system. The quality manual serves as the basis for an enterprise's quality management, and all departments and employees of the enterprise are required to strictly abide by it.
5. Quality procedure manual: The quality procedure manual details all activities and processes of an enterprise's quality management system and serves as a specific operational guide for the enterprise to implement quality management. The quality procedure manual can ensure the standardization and normalization of an enterprise's quality management activities.
6. Work documents and quality records: Work documents and quality records are the specific manifestations of an enterprise's quality management activities and can reflect the enterprise's quality management level and product quality status. The enterprise needs to properly preserve and manage work documents and quality records to ensure their authenticity, completeness, and traceability.
7. Contract: A contract is an agreement between an enterprise and a customer. The enterprise needs to provide products and services in accordance with the requirements of the contract. The quality clauses in the contract are an important basis for the enterprise's quality management. The enterprise needs to strictly fulfill its contractual obligations to ensure that the quality of products and services meets the contract requirements.
Timing and frequency of the internal quality system
1. General situation
- When all the quality system documents have been compiled, promulgated, and implemented, and have been in operation for 3 - 4 weeks, and there are problems and records available for all quality activities, the enterprise can conduct an internal quality system audit. Conducting an audit at this time can promptly identify the problems existing in the initial stage of the quality system operation and make timely adjustments and improvements.
- Conduct routine audits according to the annual audit plan. Regular audits can ensure the continuous and effective operation of the quality system and timely identify and solve potential problems.
2. Special circumstances
- When a serious quality problem occurs or there are serious complaints from users, the enterprise needs to immediately conduct an internal quality system audit, find out the cause of the problem, take effective corrective measures, and prevent the problem from recurring.
- When there are significant changes in the enterprise's leadership, subordination relationship, internal organization, products, quality policy and objectives, production technology and equipment, and production sites, etc., the enterprise needs to conduct an internal quality system audit to ensure that the quality system can adapt to these changes and continue to operate effectively.
- When a second- or third-party audit or an audit required by laws and regulations is about to be conducted, the enterprise needs to conduct an internal quality system audit and make good preparations for the audit to ensure a smooth pass of the external audit.
- After passing the third - party audit, the enterprise obtains the certification and registration qualification and the corresponding certificate. When the certificate is about to expire and the enterprise wishes to maintain the certification qualification, it needs to conduct an internal quality system audit, comprehensively inspect and evaluate the quality system to ensure compliance with the certification requirements.
Types of audit plans
1. Centralized audit plan: Audit all departments and elements involved in the quality system at one time. This audit method can comprehensively and systematically inspect the quality system and discover problems more comprehensively, but it requires more time and manpower.
2. Rolling audit plan: Conduct an audit of one or several departments or elements once a month and carry it out month by month. All departments and elements will be audited at least once within a year. This audit method is relatively flexible, capable of timely detecting and resolving local problems, and at the same time, it will not have a significant impact on the normal production and business activities of the enterprise.
Review steps
1. Develop an audit plan: Clearly define the purpose, scope, methods, time schedule, and personnel division of labor for the audit, etc., to provide guidance for the audit work.
2. Form an internal audit team: Select personnel with professional knowledge and audit experience to form an internal audit team to ensure the smooth progress of the audit work.
3. Develop an implementation plan: Based on the audit plan, develop a specific implementation plan to clarify the audit process and steps.
4. Collect and review relevant documents: Collect documents and materials related to the quality system, including quality manuals, procedure books, working documents, and quality records, etc. Conduct a careful review to understand the operation of the quality system.
5. Compile an inspection checklist: Compile an inspection checklist based on the scope and requirements of the audit, clarify the content and key points of the audit, and ensure the comprehensiveness and accuracy of the audit work.
6. Hold the first meeting: Introduce the purpose, scope, methods, and time schedule of the audit to the audited department to obtain the support and cooperation of the audited department.
7. On-site audit: In accordance with the content of the checklist, inspect and evaluate the actual work of the audited department, collect evidence, and identify problems.
8. Hold the closing meeting: Notify the audited department of the audit results, put forward improvement suggestions, and require the audited department to formulate corrective actions and complete the rectification within a specified time limit.
9. Proposal, approval and authorization of corrective actions: The audited department shall propose corrective actions based on the audit results. The internal audit team shall evaluate and approve the corrective actions, and implement them after obtaining the authorization from the management.
10. Tracking and verification of corrective actions: The internal audit team tracks and verifies the implementation of corrective actions to ensure that the corrective actions are effectively carried out and the problems are completely resolved.
11. Comprehensive analysis of the audit results of each department and element: Summarize and analyze the problems discovered during the audit process, identify the root causes and commonalities of the problems, and provide a basis for the improvement of the enterprise's quality management system.
12. Compilation of the internal quality system audit summary report: Compile the audit summary report, summarize the situation and results of the audit work, put forward improvement suggestions and measures, and submit it to the management for approval.
Classification and definition of audit defects
1. Nonconformity: Failure to meet the requirements of laws, regulations, quality assurance standards, quality manuals, quality plans, contracts, various written procedures, and work instructions constitutes nonconformity. Nonconformities are usually classified into the following three categories:
Main disadvantages
- Obvious major non - conformities with ISO9000, such as serious loopholes in the key links of the quality management system, which may lead to major problems in product quality.
- There are currently important operations without established operation procedures, which results in a lack of norms and guidance for the work and makes it prone to errors and confusion.
- Failure to execute according to the established operating procedures, resulting in obvious ineffectiveness of the operation or serious defects. For example, during the production process, operations are not carried out in accordance with the operating rules, leading to a significant increase in the unqualified rate of products.
- There are many minor defects scattered across many departments. If there are more than 5 new individual defects, it indicates that there are widespread problems in the enterprise's quality management, and comprehensive rectification is required.
- There are many minor defects concentrated in the same department, indicating that there are flaws in the quality system of this department. It is necessary to conduct in - depth analysis and improvement of the quality management system of this department.
Minor defects
- Minor defects in the system, such as some small errors or non - standard aspects in the documents.
- A single event during execution, such as a single violation operation by an individual employee.
- Occasional oversights, such as temporary errors caused by force majeure factors.
Observation item: There are currently no non-conformities, but there is a trend of becoming non-conforming. The enterprise organization can do better and needs to take timely measures for improvement to prevent the problem from deteriorating further.
Definition of quality system audit
Quality system audit is a systematic and independent review to determine whether the activities and relevant results of the quality system comply with relevant standards or documents, and whether the provisions of the quality management system documents are effectively implemented and suitable for achieving the quality policy and objectives. Through the audit, problems existing in the quality system can be identified, and corrective measures can be taken in a timely manner to improve the quality management level.
Contents included in the input and output of management review
1. Input information
- Audit results: The results of internal audits and external audits can reflect the operating status and existing problems of the quality system.
- Customer feedback: Customers' opinions and suggestions are important bases for enterprises to improve the quality of products and services, and can help enterprises understand customers' needs and expectations.
- Performance of the process and conformity of the product: Evaluate whether the efficiency of the production process and the quality of the product meet the requirements, and provide references for the enterprise's continuous improvement.
- Implementation status of preventive and corrective actions: Understand the implementation effects of preventive and corrective actions, ensure that problems are thoroughly resolved, and prevent the recurrence of problems.
- Follow - up measures of previous management reviews: Check the implementation status of the improvement measures proposed in previous management reviews to ensure that the improvement work is effectively implemented.
- Changes that may affect the quality management system: such as changes in laws and regulations, changes in market demand, etc. Enterprises need to adjust the quality management system in a timely manner to adapt to these changes.
- Suggestions for improvement: Improvement suggestions from various departments and employees within the enterprise can provide ideas and directions for the improvement of the enterprise's quality management system.
2. Output information
- Improvement of the quality management system and its processes: Propose improvement measures for the quality management system and processes to enhance the effectiveness and efficiency of the quality management system.
- Product improvements related to customer requirements: Based on customer feedback and needs, improve the product to enhance its quality and market competitiveness.
- Resource requirements: Determine the resources required by the enterprise in the process of improving the quality management system, such as human, material, and financial resources, etc., to provide a basis for the enterprise's resource allocation.
Design and development input content
1. Functional and performance requirements: Defining the functions and performance indicators that a product should possess is the foundation for product design and development. For example, the functional and performance requirements of a mobile phone include call quality, screen resolution, battery life, etc.
2. Compliance with applicable laws and regulations: Products must comply with national and local laws and regulations to ensure their legality and safety. For example, food products need to meet the requirements of food safety laws and regulations.
3. Information provided by applicable previous similar designs: Referring to the design experience and data of previous similar products can avoid redundant work and improve the efficiency and quality of design.
4. Design other requirements necessary for each development: such as product appearance design requirements, packaging requirements, transportation requirements, etc. These requirements are also factors to be considered in the product design and development process.
Through what channels can non-conforming products be disposed of
1. Take measures to eliminate the identified non - conformities: Repair, rework, etc. the non - conforming products to make them meet the quality requirements. For example, reprocess the defective products to make them reach the qualified standards.
2. After being approved by relevant authorized personnel, accept non-conforming products with concession, release them, or dispose of them as scrap: In some cases, if the non-conforming products have little impact on the product's performance and pose no safety hazards to customers after evaluation, they can be accepted with concession or released after being approved by authorized personnel. Non-conforming products that cannot be repaired shall be disposed of as scrap.
3. Take measures to prevent its intended use in various applications: Isolate and label non-conforming products to prevent them from entering the normal production and use processes and avoid affecting other products or processes.
At the same time, records of the nature of nonconformities and any subsequent actions taken, including records of authorized concessions, shall be maintained. After nonconforming products have been corrected, they shall be re - verified to demonstrate conformity to requirements. When nonconformities are discovered after delivery or during use, the organization shall take actions appropriate to the effects or potential effects of the nonconformities.
The role of internal auditors
1. Supervise the operation of the quality system: Internal auditors regularly audit the quality system to monitor its operation, promptly identify problems and propose improvement suggestions to ensure the effective operation of the quality system.
2. Play an advisory role in the maintenance and improvement of the quality system: Internal auditors are familiar with all aspects of the quality system and can provide professional suggestions and solutions for the maintenance and improvement of the enterprise's quality system based on the audit results and the actual situation of the enterprise.
3. Serve as a channel and link in the communication between leaders and employees: Internal auditors can convey the requirements and expectations of leaders to employees, and at the same time, feedback the opinions and suggestions of employees to leaders, promoting communication and understanding between leaders and employees, and enhancing the cohesion and execution ability of the enterprise.
Characteristics of the QMS management model
QMS is a process-based management model. It regards quality management as a series of interrelated processes. Through the identification, analysis, and control of these processes, the goals of quality management are achieved. This management model emphasizes the optimization and continuous improvement of processes, which can improve product quality and production efficiency and enhance the competitiveness of enterprises.
II. Knowledge related to EMS (Environmental Management System)
Definition of WEEE
WEEE refers to waste electrical and electronic equipment, that is, in accordance with the No
Product level and design specifications
Ultimately, the level that a product can reach is fundamentally closely related to the product specifications set during the design stage. Design specifications are like the blueprints of a building, which meticulously plan various elements of the product, such as performance, parameters, and functions. If the design specifications are set high and reasonably, the product theoretically has the foundation to reach a relatively high level. On the contrary, if there are defects in the design specifications or the standards are too low, it is naturally difficult to improve the level of the product.
In order to ensure that products can stably meet the design specifications during mass production, it is essential to implement a review process during the design phase. This review process is like a strict checkpoint, which requires the integration of professional knowledge and experience from multiple aspects. From a technical perspective, it is necessary to examine the feasibility of the design specifications in actual production, including whether the adopted technology is mature and easy to implement. In terms of cost, it is necessary to evaluate whether the cost of producing products according to the design specifications is within an acceptable range. Regarding market demand, it is necessary to consider whether the design specifications can meet the expectations of the target customer group. Only through such a comprehensive and detailed review can we ensure that the design specifications can be stably achieved in mass production.
Supplier and Quality Management
The birth of a product often cannot do without the assistance of suppliers in providing raw materials. Suppliers are like an important link in the product production chain, and their quality management systems and standards directly affect the quality of the company's products. It can be said that the quality management of suppliers is an important part of the company's quality management and an indispensable input resource in quality management.
A dedicated organization should be established within the company to monitor this resource. This organization needs to have professional testing capabilities and strict testing standards. They should conduct comprehensive inspections of the raw materials provided by suppliers, including the physical properties, chemical characteristics, and appearance quality of the raw materials. At the same time, they should not be satisfied with the current testing results alone, but also continuously urge the suppliers to improve. A long - term cooperative relationship can be established with suppliers to share advanced quality management concepts and technologies, and help suppliers improve their production processes, thereby enhancing their overall quality management level.
Resource elements of quality management
Technical personnel
In quality management, the personnel in the company who have mastered quality management techniques are the most important resources. These technical personnel are like the core brains of quality management. They possess professional knowledge and rich experience and can formulate scientific and reasonable quality management strategies. They not only need to be familiar with the theories and methods of quality management but also understand the production processes and technical characteristics of products so that they can target their efforts in the quality management process.
Equipment and instruments
The equipment and instruments that must be used in quality management are indispensable material resources for quality management. These equipment and instruments are like the eyes and ears of quality management, and they can accurately detect various indicators of products. For example, high-precision measuring instruments can detect the dimensional accuracy of products, and advanced testing equipment can analyze the chemical composition of products. Through the use of these equipment and instruments, problems in product quality can be discovered in a timely manner, providing strong support for quality management.
Quality management system
The core of process control in quality management is to establish a set of quality management systems that can operate effectively. This system is like a precision machine, with each link interrelated and mutually restrictive. It includes various aspects such as the formulation of quality policies and objectives, the clarification of responsibilities and authorities, the management of quality documents and records, the determination of management items, measures for quality improvement, 4M change management, management when abnormalities occur, corrective and preventive countermeasures, supplier management, and mass production evaluation. Only by establishing such a comprehensive quality management system and ensuring its effective operation can we achieve comprehensive and continuous control over product quality.
System composition of modern quality management
Quality assurance system
The quality assurance system in modern quality management covers multiple important aspects. The quality policy and objectives provide a direction for quality management, clearly defining the company's pursuit and commitment in terms of quality. The division of responsibilities and authorities ensures that the duties of each position in quality management are clear, avoiding the phenomenon of shifting blame. The quality system is the framework of the entire quality management, standardizing the processes and standards of various tasks. Quality document management ensures the integrity and accuracy of relevant documents, providing a basis for quality management. Quality record management records the entire process of quality management, facilitating traceability and analysis. Management items clarify the key points and critical links of quality management. Quality improvement is the driving force for continuous quality improvement. 4M change management can promptly respond to changes in personnel, machines, materials, and methods, ensuring the stability of quality. Management in case of abnormalities can quickly handle emergencies and reduce losses. Corrective and preventive measures can fundamentally solve quality problems and prevent their recurrence. Supplier management strengthens cooperation with suppliers to ensure the quality of raw materials. Mass production evaluation comprehensively assesses the quality of mass - produced products.
Process guarantee system
The process assurance system also plays a crucial role in modern quality management. The compilation of operation instructions provides detailed operation guidelines for employees, ensuring that each process can be carried out according to the standards; the determination of operation instructions guarantees the accuracy and effectiveness of the instructions; operation implementation is the process of transforming design and plans into actual products, which needs to be carried out strictly in accordance with the operation instructions; the management of recycled materials ensures the rational use of recycled materials and avoids impacts on product quality; the management of equipment and tooling fixtures guarantees the normal operation of production equipment and the accuracy of tooling fixtures; the management and identification of batches facilitate the traceability and management of products in different batches; process control monitors the operation of the process in real - time and promptly discovers and solves problems.
Check the system
The inspection system is an important defense line in quality management. The setting of inspection points should be based on the characteristics of the product and the production process to reasonably determine the links and positions that need to be inspected; the preparation of the inspection specification clarifies the inspection standards and methods; the determination of the inspection specification ensures the scientific nature and practicality of the specification; the adjustment of inspection strictness can be flexibly controlled according to the actual situation to ensure that problems can be effectively detected without excessively increasing costs; the implementation of inspection is the specific inspection operation process, which needs to be carried out strictly in accordance with the inspection specification; the management and identification of batches facilitate the classified inspection and management of products in different batches; the management of inspection equipment ensures the accuracy and reliability of inspection equipment; the management of safety specification parts ensures that parts related to safety meet relevant standards.
Quality cost
Definition and Composition
Quality costs refer to the expenses incurred to ensure and guarantee satisfactory quality and the losses caused by failing to achieve satisfactory quality. Quality costs are mainly composed of prevention costs, appraisal costs, failure costs, and quality costs of external activities.
Prevention cost
Prevention cost is the expense invested to prevent the occurrence of quality problems. It includes the fees for safety specification certifications in various regions and countries, such as external certifications of the quality system and ISO9000 certification. These certifications can enhance the company's quality image and market competitiveness; the fees for guiding and assisting suppliers in implementing the source assurance system. By helping suppliers improve their quality management level, quality problems can be reduced at the source; the packaging fees for incoming materials. Reasonable packaging can protect raw materials from damage during transportation and storage; the expenses invested in advance during the inspection of incoming materials, the manufacturing process, and the inspection process of finished products. Conducting inspections in advance can detect potential quality problems in a timely manner; the education and training fees for employees. Improving employees' quality awareness and skill levels can help reduce quality problems caused by human factors.
Appraisal cost
Appraisal costs are the expenses incurred to determine whether products meet quality requirements. The personnel costs of incoming material inspection (IQC) and the costs of destructive testing for incoming materials. Through the inspection of incoming materials, it is ensured that the raw materials entering the production process meet the quality standards; the personnel costs of in-process inspection (IPQC), on-line inspection (FQC), finished product inspection (OQC), etc., and the costs of consumables used. Multiple inspections are carried out during the production process to promptly detect and correct quality problems; the costs of entrusting external appraisals and tests, as well as the costs of external calibration of measuring instruments. With the help of external professional institutions, the accuracy of the test results is ensured.
Loss cost
Loss costs include internal loss costs and external loss costs. Internal loss costs are the losses caused by the failure of products to meet quality requirements before delivery. Common examples include re - providing services, processing, reworking, repairing, retesting, scrapping, and manufacturing shutdowns due to quality problems. All these will increase production costs and reduce production efficiency. External loss costs are the expenses incurred after delivery due to the failure of products to meet quality requirements, such as product maintenance and repair, warranties and returns, direct costs, discounted sales due to product defects, product recall fees, liability compensation fees, etc. These will not only bring economic losses to the company but also affect the company's reputation.
External activity cost
External activity costs consist of external quality assurance costs. It refers to the expenses paid to provide customers with the required objective evidence under the contract situation. For example, many customers will require suppliers to provide material certificates and entrust external inspection agencies to issue test reports. These expenses all belong to external activity costs.
Knowledge related to quality assurance
IQC function
IQC (Incoming Quality Control) plays an important role in the manufacturing industry. It is responsible for inspecting the components provided by suppliers in accordance with engineering drawings, contracts, samples, and suppliers' shipping inspection reports. For qualified products, they are allowed to be stored in the warehouse and enter the production process; for unqualified products, measures such as returning the goods, selective inspection, and special acceptance are taken. At the same time, IQC is also responsible for tracking defective situations, supervising suppliers to take improvement countermeasures, and preventing the recurrence of defects, so as to ensure that the quality of the components entering the production process meets the requirements.
Main factors affecting product quality
In the manufacturing industry, there are generally four main factors that directly affect product quality: design, incoming materials, the manufacturing process, and storage and transportation. The proportion of each main factor in quality varies across different industries. In the electronic assembly industry, design accounts for 30%, incoming materials account for 30% - 40%, manufacturing accounts for 30%, and storage and transportation account for 5% - 10%. In the electronic component industry, design accounts for 10%, incoming materials account for 30%, manufacturing accounts for 40% - 50%, and storage and transportation account for 1% - 10%. In the plastics industry, design accounts for 1% - 5%, incoming materials account for 40% - 50%, manufacturing accounts for 40%, and storage and transportation account for 1% - 5%. Understanding the proportion of each main factor in quality in different industries helps enterprises strengthen quality management in a targeted manner.
IQC Sampling Plan
The IQC sampling plan can be divided into attribute sampling, variable sampling, and special inspection and analysis sampling. Attribute sampling involves inspecting the samples of a batch of products for defects or non - conforming products, such as burrs, stains, short legs, non - compliant dimensions, and damages. The quality status of the products is evaluated by counting the number of defects and non - conformities. Variable sampling, on the other hand, is to inspect various important and measurable characteristics of the materials, such as dimensions, weight, and strength. Special inspection and analysis sampling mainly conducts reliability analysis or component analysis to gain in - depth understanding of the performance and quality of the products.